Detect amount of players in server

I was searching for a way to be able to detect if there is a certain amount of players in server.

My goal is to detect if there is e.g. 15 players on server, then the votekick would be enabled.
The reason why I'm trying to find this is because on empty servers, 2 players can join 1 server which has votekick enabled.
If a 3rd player joins, both of them can kick you out, just resulting in an abuse of power.

“No person has the power to have everything they want, but it is in their power not to want what they don’t have, and to cheerfully put to good use what they do have.” – Seneca